This section provides background information related to the present disclosure, which is not necessarily prior art. FIG. 19 depicts a schematic view of a vapor compression cycle, such as an air conditioning cycle or refrigeration cycle, in accordance with the prior art. More specifically, a compressor 2 may compress a working fluid such as a refrigerant into a high pressure gas and force it into a condenser 4, where heat is removed from the gas phase refrigerant in an attempt to further lower the temperature of the compressed refrigerant. The gas phase refrigerant is condensed to a liquid phase refrigerant, exits condenser 4 and proceeds to pass through a high pressure flow passage 6 of an internal heat exchanger 7 where the liquid phase refrigerant is further cooled by using the cool refrigerant that exits from the evaporator 10. Upon passing through the internal heat exchanger 7, the compressed liquid refrigerant passes through a thermostatic expansion valve (“TXV”) 8 that controls the amount of refrigerant flow into an evaporator 10 thereby controlling the superheat at the outlet of evaporator 10. In controlling the amount of superheat exiting evaporator 10, a temperature detecting device 12 may be used to adjust an amount of refrigerant entering evaporator 10. The temperature detecting device 12 is commonly integrated into the structure of TXV 8. Upon passing temperature detecting device 12, refrigerant then passes into a low pressure flow passage 14 of the internal heat exchanger 7. The high pressure flow passage 6 is located next to the low pressure flow passage 14, such that refrigerant passing through the high pressure flow passage 6 expels heat that is absorbed by refrigerant passing through the low pressure flow passage 14. Upon exiting the low pressure flow passage 14, refrigerant enters compressor 2 where it is again compressed.
The above vapor compression cycle has proven satisfactory for its intended purpose, but a need exists for improvement of its efficiency.